Multiple Alleles and Blood Types

• Multiple Alleles - when more than two alleles are available for a trait in a population

• Ex. 3 Alleles available in human Blood Types

  • I^A - Type A

  • I^B - Type B

  • i - Type O

• I^A and I^B are codominant over i​

• Results in 4 Phenotypes

  • Type A

  • Type B

  • Type AB

  • Type O

Multiple Alleles and Blood Types

Multiple Alleles and Blood Types

​Type O is the universal donor because Type O blood cells do not contain antigens.

• ​Genotypes for Type A

• Genotypes for Type B

• Genotype for Type AB

• Genotype for Type O